c++ UVA 579 - ClockHands wrong answer

我试图解决这个问题，但系统一直给我"错误的答案"。我检查了其他人的解决方案，我确信我的算法是正确的。有人能帮我吗？非常感谢。问题：UVA 579 ClockHands

#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
int main()
{
    int hour, minute;
    float hour_degree, minute_degree;
    float total;
    while(scanf("%d:%d",&hour, &minute) == 2)
    {
        if( hour == 0 && minute == 0)
            break;
        minute_degree = minute * 6;
        hour_degree = hour * 30 + float(minute / 2);
        total = fabs(hour_degree - minute_degree);
        if(total > 180)
            total = fabs(360 - total);
        printf("%.3fn", total); 
    }
    return 0;
}